EXPERIMENTS PROJECTED FOR YEAR THREE: We shall continue to investigate the mechanism of reverse transcription. This work will involve further characterization of the sequence of the 5' and 3' termini of Rous sarcoma virus of all of Mo-MuLV. For this work, the newly developed RNA sequencing technologies will be used. Our work will also involve detailed structural analysis of viral messenger RNA molecules. The sequences on both sides of the suspected splice point on the viral genome will be studied as well as the sequence of the ends of the viral messenger RNA molecules. The role of specific enzymes involved in messenger RNA processing will also be investigated.